U.S. patent application number 10/749513 was filed with the patent office on 2005-05-12 for face masks.
Invention is credited to Bishop, Giles Andrew, Bower, David, Nash, John, Neame, Simon, Pagan, Eric, Stinton, Clive, Williams, Lois Rebecca.
Application Number | 20050098183 10/749513 |
Document ID | / |
Family ID | 9951171 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050098183 |
Kind Code |
A1 |
Nash, John ; et al. |
May 12, 2005 |
Face masks
Abstract
A face mask has a relatively soft canopy and a more rigid
reinforcement member moulded together from different plastics as
two shots in a dual-shot moulding process. The peripheral sealing
edge of the canopy is tapered to a reduced thickness to increase
its flexibility. The reinforcement member is a frame with
radially-extending arms supporting respectively a gas port by which
gas can enter the mask, a valve that allows air into the mask when
there is an inadequate supply at the gas port and a selectively
closable vent. The mask is secured to the patient's head by a
harness attached to ends of the harness arms.
Inventors: |
Nash, John; (Hythe, GB)
; Williams, Lois Rebecca; (Hythe, GB) ; Neame,
Simon; (Broadstairs, GB) ; Pagan, Eric;
(Hythe, GB) ; Bishop, Giles Andrew; (Canterbury,
GB) ; Bower, David; (Herne Bay, GB) ; Stinton,
Clive; (Folkestone, GB) |
Correspondence
Address: |
LOUIS WOO
LAW OFFICE OF LOUIS WOO
717 NORTH FAYETTE STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
9951171 |
Appl. No.: |
10/749513 |
Filed: |
January 2, 2004 |
Current U.S.
Class: |
128/206.21 ;
128/206.27 |
Current CPC
Class: |
A61M 2202/0225 20130101;
A61M 16/06 20130101; A61M 16/208 20130101; B29C 45/1676 20130101;
A61M 16/0616 20140204; B29C 2791/001 20130101; A61J 15/0003
20130101; A61M 16/206 20140204; A61M 16/0683 20130101; A61M 16/209
20140204; A61M 2202/0225 20130101; A61M 2202/0085 20130101 |
Class at
Publication: |
128/206.21 ;
128/206.27 |
International
Class: |
A62B 018/02; A62B
018/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2003 |
GB |
0300875.2 |
Claims
What we claim is:
1. A face mask of a plastics material comprising: a relatively soft
canopy member having a peripheral sealing edge providing a seal
with the skin around the nose and mouth of a patient, said canopy
member being moulded as one shot in a dual-shot moulding process; a
relatively rigid reinforcement member, said reinforcement member
being moulded integrally with said canopy member as another shot in
the dual-shot moulding process; and a gas port by which gas can
enter the mask.
2. A face mask according to claim 1, wherein said peripheral
sealing edge of said canopy member is tapered to a reduced
thickness and an increased flexibility at its edge.
3. A face mask according to claim 1, wherein said gas port is
provided on said reinforcement member.
4. A face mask according to claim 1, wherein said gas port has a
gas connector projecting therefrom for connection to a gas supply
tube, and wherein said port is located in line with the mouth of
the patient and said connector is angled such that it projects down
when the mask is applied to the patient's face in an upright
position.
5. A face mask according to claim 1 including a valve separate from
said gas port, wherein said valve is arranged to allow air to flow
into the mask when there is an inadequate supply at said gas
port.
6. A face mask according to claim 5, wherein said valve is provided
on said reinforcement member.
7. A face mask according to claim 1 including a selectively
closable vent that can be opened to allow flow of gas out of the
mask.
8. A face mask according to claim 7, wherein said vent includes a
cap member movable between two discrete positions where said vent
is open or closed respectively.
9. A face mask according to claim 7, wherein said vent is provided
on said reinforcement member.
10. A face mask according to claim 1, wherein said reinforcement
member is a frame with a plurality of radially-extending arms.
11. A face mask according to claim 10, wherein two of said arms
extend towards opposite edges of mask and are terminated by lateral
bars extending substantially parallel to an edge of the mask.
12. A face mask according to claim 11 including a harness arranged
to extend around the head of the patient, and wherein said lateral
bars support a fastener to which said harness is attached.
13. A face mask according to claim 10, wherein said frame includes
three arms supporting respectively a gas port, a valve to allow gas
to enter the mask and a vent that can be opened to allow gas to
flow out of the mask.
14. A face mask according to claim 1 including a harness arranged
to extend around the head of the patient and wherein said harness
is attached at opposite ends with said reinforcement member.
15. A face mask according to claim 14, wherein the opposite ends of
said harness are of triangular shape having a free end extending
rearwardly and wherein the free end is adjustably attachable with a
part of said harness.
16. A face mask assembly including a harness and a mask, wherein
said mask is of a plastics material and comprises: a relatively
soft canopy member having a peripheral sealing edge providing a
seal with the skin around the nose and mouth of a patient, said
canopy member being moulded as one shot in a dual-shot moulding
process; a relatively rigid reinforcement member, said
reinforcement member being moulded integrally with said canopy
member as another shot in the dual-shot moulding process; and a gas
port provided on said reinforcement member by which gas can enter
the mask, and wherein said harness is arranged to extend around the
head of the patient and is attached with said reinforcement
member.
17. A face mask assembly according to claim 16, wherein said mask
includes a valve on said reinforcement member and separate from
said gas port, said valve being arranged to allow air to enter the
mask when there is an inadequate supply at said gas port, and
wherein said mask includes a selectively closable vent provided on
said reinforcement member, said vent being openable to allow gas
out of the mask.
18. A method of making a face mask comprising the steps of:
moulding a first component in a mould from a relatively high
temperature plastics material and subsequently moulding a second
component from a relatively low temperature plastics material
directly on said first component while said first component is in
said mould.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to face masks.
[0002] Face masks are used to supply gas to a patient for various
purposes and are designed to seal with the skin surface around the
nose and mouth. There are many different forms of face mask
currently available but often these suffer from disadvantages such
as large bulk, weight, discomfort in use or poor sealing.
BRIEF SUMMARY OF THE INVENTION
[0003] It is an object of the present invention to provide an
alternative face mask.
[0004] According to one aspect of the present invention there is
provided a face mask of a plastics material comprising a relatively
soft canopy member having a peripheral sealing edge providing a
seal with the skin around the nose and mouth of a patient, the
canopy member being moulded as one shot in a dual-shot moulding
process, a relatively rigid reinforcement member being moulded
integrally with the canopy member as another shot in the dual-shot
moulding process, and the mask having a gas port by which gas can
enter the mask.
[0005] The peripheral sealing edge of the canopy preferably is
tapered to a reduced thickness and an increased flexibility at its
edge. The gas port is preferably provided on the reinforcement
member. The gas port may have a connector projecting therefrom for
connection to a gas supply tube, the port being located in line
with the mouth of the patient and the connector being angled such
that it projects down when the mask is applied to the patient's
face in an upright position. The face mask preferably includes a
valve separate from the gas port, the valve being arranged to allow
air to flow into the mask when there is an inadequate supply at the
gas port. The valve may be provided on the reinforcement member.
The mask preferably includes selectively closable vent means that
can be opened to allow flow of gas out of the mask, and the vent
means may include a cap member movable between two discrete
positions where the vent is open or closed respectively. The vent
means is preferably provided on the reinforcement member. The
reinforcement member is preferably a frame with a plurality of
radially-extending arms. Two of the arms may extend towards
opposite edges of the mask and be terminated by lateral bars
extending substantially parallel to the edge of the mask. The
lateral bars may support fastening means for a harness extending
around the head of the patient. The mask preferably includes three
arms supporting respectively a gas port, a valve to allow gas to
enter the mask and a vent that can be opened to allow gas to flow
out of the mask. The mask may include a harness adapted to extend
around the head of the patient and attached at opposite ends with
the reinforcement member. Opposite ends of the harness may be of
triangular shape having a free end extending rearwardly, the free
end being adjustably attachable with a part of the harness.
[0006] According to another aspect of the present invention there
is provided a method of making a face mask comprising the steps of
moulding a first component in a mould from a relatively high
temperature plastics material and subsequently moulding a second
component from a relatively low temperature plastics material
directly on the first component while the first component is in the
mould.
[0007] According to a further aspect of the present invention there
is provided a face mask made by a method according to the above
other aspect of the invention.
[0008] A face mask according to the present invention will now be
described, by way of example, with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a front view of the mask;
[0010] FIG. 2 is a side elevation view of the mask on the face of a
patient;
[0011] FIG. 3 is a sectional side elevation view of the mask;
[0012] FIGS. 4 and 5 are sectional side elevation views of a part
of the mask to an enlarged scale indicating how it seals on the
face;
[0013] FIG. 6 is a perspective view of a controlled leak
device;
[0014] FIG. 7 is a sectional side elevation view of an
anti-asphyxia valve;
[0015] FIG. 8 shows two straps used in the mask harness;
[0016] FIG. 9 is a side elevation view of the mask showing an
alternative harness;
[0017] FIG. 10 is an elevation view of the edge of the mask showing
a tube access; and
[0018] FIG. 11 is a sectional view of the tube access of FIG.
10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] With reference first to FIGS. 1 to 5, the mask comprises two
parts, namely a canopy 1 and a support frame 2. The canopy 1 is
moulded of a relatively soft, flexible plastics material, such as,
SEBS styrene ethylene butadiene styrene, whereas the support frame
2 is moulded of a harder material, such as a polypropylene
copolymer. The canopy 1 and support frame 2 are moulded integrally
with one another by a dual-shot moulding process in which the
higher temperature plastics material forming the frame 2 is moulded
first in a mould cavity, then the mould is enlarged to form a
cavity for the canopy, which is subsequently moulded from a lower
temperature plastics material. This results in the canopy and
support frame being integrally bonded together.
[0020] The canopy 1 is of generally triangular shape with a
peripheral edge 10 shaped to extend under the mouth, up the cheeks,
along the sides and across the nose. The canopy 1 has a domed
internal cavity 11 in which the nose is received. The edge 10 is
curved inwardly into the cavity in a C shape so that, when the mask
is placed against the face, as shown in FIGS. 4 and 5, a curved
contact region 12 contacts the skin with the lip 13 being on or
spaced slightly above the skin. The canopy 1 varies in thickness
from about 2 mm across most of its surface tapering to about 1.5 mm
in the contact region 12 and to about 0.7 mm at the lip 13. This
makes the edge 10 very flexible. The seal with the patient's skin
could be further enhanced by an adhesive material on the contact
region.
[0021] The frame member 2 has a generally star shape with three
radially-extending arms 20, 21 and 22. One arm 20 projects down and
is formed with a gas connector port 23 positioned in line with the
patient's mouth and angled downwardly at an angle of about
20.degree. to the horizontal when mounted on the patient's face in
an upright position. A second arm 21 projects upwardly to the left,
as viewed in FIG. 1, and includes a controlled leak device 30 to be
described in greater detail later. The second arm 21 is terminated
by a lateral bar 24 extending parallel to the edge of the mask in
the region of the patient's right cheek. The third arm 22 projects
upwardly towards the right and includes an anti-asphyxia valve 25,
as described in greater detail later. The third arm is terminated
by a lateral bar 26 extending parallel to the edge of the mask in
the region of the patient's left cheek.
[0022] Moulding the face mask in a dual-shot process gives various
advantages. It enables the mask to made very thin and light in
weight with a very flexible seal whilst having sufficient rigidity
across its central portion to support the connector and the various
other components without deformation. Because the mask can be made
thin, the upper part of the mask can be shaped to follow closely
the profile of the nose. This reduces interference to the patient's
eyesight and can make the mask less claustrophobic than some
previous masks. The dual-shot process also enables the mask to be
made with high transparency so that the part of the face enclosed
by the mask can be seen clearly by the clinician.
[0023] The controlled leak device 30 is shown most clearly in FIGS.
6 and 7 and is formed of two components, namely a base 31 and a cap
32. The base 31 comprises a circular plate 33 secured in an
aperture in the frame 2. The plate 33 has three gas passages 34
extending through it and a central stem 35 projecting from the
external surface. The stem 35 is hollow and cylindrical with a male
luer slip surface to receive a female connector. The stem 35 also
has key formations 36 on its outer surface. The cap 32 has a plate
37 of the same diameter as the base plate 33 and with three
openings 38 spaced in the same manner as the passages 34. A hollow
sleeve 39 projects from the centre of the plate 33. The sleeve 39
is shaped to fit on the stem 35 and has keyway formations on its
inner surface (not shown). The key and keyway formations are
arranged to prevent rotation of the cap 32 on the base 31 and to
ensure that the cap can only be fitted on the base either with the
openings 38 aligned with the gas passages 34 or with them not
aligned and thereby preventing flow of gas. When the cap 32 is
mounted on the base with the openings 38 aligned with the gas
passages this permits a small flow of gas through the leak device.
This is sufficient to allow air exhaled by the patient to flow out
through the leak without enabling pressure of gas supplied to the
mask to fall below the level needed for CPAP ventilation. When the
cap 32 is removed, a tube (not shown) can be connected to the
tapered stem 35 for carbon dioxide sampling purposes.
[0024] The anti-asphyxia valve 25 is shown in FIG. 7 and includes a
rigid plate 70, which is flat on its upper, outer surface 71 and
has a concave, domed recess 72 on its lower, inner surface. Four
holes 73 extend through the plate 70 between the recess 72 and the
outer surface 71 and are equally distributed around the edge of the
recess. A narrow ledge 74 extends around the outside of the recess
72. The valve 25 also includes a flexible, resilient diaphragm 75
providing a valve member for the valve. The diaphragm 75 has a
peripheral ledge 76, which is clamped on the ledge 74 by a ring
(not shown), and a domed central portion 77 with a central aperture
78. The radius of curvature of the domed portion 77 in its natural
state is greater than that of the recess 72 so that it is spaced
away from the recess and allows free flow of gas through the
aperture 78 and holes 73. When the internal pressure within the
mask is raised, the domed portion 77 is forced outwardly, that is,
upwardly into contact with the recess 72, thereby sealing the holes
73 closed. The valve 25, therefore, closes when there is high gas
pressure within the mask but opens when gas pressure drops, thereby
permitting the patient to breath atmospheric air in through the
valve. Other, conventional forms of valve could be used to allow
the patient to inhale via the valve should there be an obstruction
to gas flow to the inlet port 23. Previous anti-asphyxia valves
have been incorporated into the gas inlet port connection but this
has the disadvantage of increasing the bulk at the inlet and
thereby increasing the bending moment exerted on the mask by the
associated inlet tubing.
[0025] Attached to both lateral bars 24 and 26 is a strip 27 and 28
of a hook fastening material, such as of the kind sold under the
Velcro trade mark (Velcro is a Registered Trade Mark of Velcro BV),
which is used to secure an end of a harness 40. The harness 40
comprises two flexible, elastic straps 41 and 42, as shown in FIG.
8, which both have a pad 43 and 44 of a loop fastening material at
one end so that they can be secured with the strips 27 and 28 on
the mask frame 2. At their other ends, one strap 41 has a pad 45 of
a hook material and the other strap 42 has a pad 46 of a loop
material. Opposite ends of the straps 41 and 42 are enlarged
laterally to accommodate the pads 43 to 46. In this way, the straps
41 and 42 can be secured with one another at one end at the back of
the patient's head and can be secured at their other ends with the
mask frame 2. The arrangement allows for the straps to be secured
to the frame and to one another at any angle, thereby allowing
flexibility in positioning of the harness so as to accommodate a
variety of patients.
[0026] An alternative harness arrangement 140 is illustrated in
FIG. 9. This harness 140 has two straps 141, only one of which is
shown, which are fastened together at the back of the head by hook
and loop fastening material (not shown). The straps 141 are
fastened to the mask itself by means of two posts 142 and 143
projecting from the side of the mask and spaced one above the
other, which extend through apertures 142' and 143' in the straps.
The forward end of the straps 141 is of triangular shape having a
lateral portion 144 extending upwardly at an angle of about
90.degree. to the main part of the strap, and a
rearwardly-extending portion 145 extending rearwardly and
downwardly at an angle of about 45.degree. to the upper end of the
lateral portion. The rearwardly-extending portion 145 has a free
rear end to which is attached a pad 146 of a hook or loop material,
which attaches to a cooperating pad 147 on the main part of the
strap. This arrangement enables the pressure exerted by the mask on
the face to be adjusted to alter its distribution. Pressure exerted
by the upper part of the mask can be increased or reduced by
appropriately moving the end of the portion 145 to attach it to a
part of the pad 147 that is further back or further forwards. The
straps 141 each have a quick-release tab 148 in the region of the
upper aperture 142'. One or both of these tabs 148 can be pulled
down to release the harness 141 from the mask.
[0027] Various modifications are possible to the mask. The edge
seal of the mask may be modified to allow a nasogastric tube 90 to
pass through the edge 10, as shown in FIGS. 10 and 11. In this
arrangement the edge of the mask is moulded with a keyhole-shape
formation 91 of reduced thickness, which can be easily torn or cut.
The keyhole-shape formation 91 has a very narrow entrance portion
slit 92 extending to the edge, and a circular sleeve portion 93
located above it and projecting a short distance inwardly. When
used without a nasogastric tube, this formation is left in place so
that there is no path for gas leakage in this region. When a
nasogastric tube is to be used, the keyhole-shape formation is torn
or cut to form a keyhole-shape aperture so that the tube 90 can be
pushed sideways in through the narrow part of the aperture, which
may be self-closing, and located in the circular, sleeve part of
the aperture where it is a close, sealing fit. If the mask needs to
be removed at any time, the tube can be easily peeled out of the
aperture so that its patient end can be left in place in the
patient and its machine end need not be disconnected from any
apparatus to which it is connected. The mask can be subsequently
replaced on the patient after having pushed the nasogastric tube
into the aperture.
* * * * *